Ric,

For the replacement blocks, I used stainless blocks that I had laying around in my garage. They have a 1" wheel (sheave?). The body that holds the center pin in place runs up one side of the wheel, across the top (to form a retaining loop) and back down the other side of the wheel. For the two blocks fastened to the aft of the centerboard I had to modify the body by cutting the retaining loop at the top-center and then spreading the two sides of the body so that it fit around the aft of the centerboard. The bolts that run through the centerboard go through each side of the block body.

I did notice that the centerboard had a slot cut into it where the bolt runs through. This slot appears to be for the type of block that you used.

My new blocks may be the weak link in the system now. Time will tell.

Chris